[src/trunk]: src/sys Add KASAN instrumentation on strcat/strchr/strrchr.

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bcd5e6d4e01c
branches:  trunk
changeset: 970762:bcd5e6d4e01c
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri Apr 03 18:44:50 2020 +0000

description:
Add KASAN instrumentation on strcat/strchr/strrchr.

diffstat:

 sys/kern/subr_asan.c      |  35 +++++++++++++++++++++++++++++++++--
 sys/lib/libkern/libkern.h |  11 +++++++++--
 2 files changed, 42 insertions(+), 4 deletions(-)

diffs (81 lines):

diff -r 3fa09c4667e3 -r bcd5e6d4e01c sys/kern/subr_asan.c
--- a/sys/kern/subr_asan.c      Fri Apr 03 18:39:15 2020 +0000
+++ b/sys/kern/subr_asan.c      Fri Apr 03 18:44:50 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_asan.c,v 1.19 2020/04/03 18:12:39 maxv Exp $      */
+/*     $NetBSD: subr_asan.c,v 1.20 2020/04/03 18:44:50 maxv Exp $      */
 
 /*
  * Copyright (c) 2018-2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_asan.c,v 1.19 2020/04/03 18:12:39 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_asan.c,v 1.20 2020/04/03 18:44:50 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -507,6 +507,37 @@
        return (s - str);
 }
 
+char *
+kasan_strcat(char *dst, const char *src)
+{
+       size_t ldst, lsrc;
+
+       ldst = __builtin_strlen(dst);
+       lsrc = __builtin_strlen(src);
+       kasan_shadow_check((unsigned long)dst, ldst + lsrc + 1, true,
+           __RET_ADDR);
+       kasan_shadow_check((unsigned long)src, lsrc + 1, false,
+           __RET_ADDR);
+
+       return __builtin_strcat(dst, src);
+}
+
+char *
+kasan_strchr(const char *s, int c)
+{
+       kasan_shadow_check((unsigned long)s, __builtin_strlen(s) + 1, false,
+           __RET_ADDR);
+       return __builtin_strchr(s, c);
+}
+
+char *
+kasan_strrchr(const char *s, int c)
+{
+       kasan_shadow_check((unsigned long)s, __builtin_strlen(s) + 1, false,
+           __RET_ADDR);
+       return __builtin_strrchr(s, c);
+}
+
 #undef kcopy
 #undef copystr
 #undef copyinstr
diff -r 3fa09c4667e3 -r bcd5e6d4e01c sys/lib/libkern/libkern.h
--- a/sys/lib/libkern/libkern.h Fri Apr 03 18:39:15 2020 +0000
+++ b/sys/lib/libkern/libkern.h Fri Apr 03 18:44:50 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: libkern.h,v 1.137 2019/12/14 17:23:47 riastradh Exp $  */
+/*     $NetBSD: libkern.h,v 1.138 2020/04/03 18:44:50 maxv Exp $       */
 
 /*-
  * Copyright (c) 1992, 1993
@@ -430,7 +430,14 @@
 #endif
 
 /* These exist in GCC 3.x, but we don't bother. */
-#if defined(_KERNEL) && defined(KMSAN)
+#if defined(_KERNEL) && defined(KASAN)
+char   *kasan_strcat(char *, const char *);
+char   *kasan_strchr(const char *, int);
+char   *kasan_strrchr(const char *, int);
+#define        strcat(d, s)            kasan_strcat(d, s)
+#define        strchr(s, c)            kasan_strchr(s, c)
+#define        strrchr(s, c)           kasan_strrchr(s, c)
+#elif defined(_KERNEL) && defined(KMSAN)
 char   *kmsan_strcat(char *, const char *);
 char   *kmsan_strchr(const char *, int);
 char   *kmsan_strrchr(const char *, int);